Bottom morphology and lithodynamic processes in the outfall offshore mouth zone and in the delta of the Northern Dvina River

Oceanology ◽  
2017 ◽  
Vol 57 (2) ◽  
pp. 315-327
Author(s):  
N. A. Rimskii-Korsakov ◽  
V. N. Korotaev ◽  
V. V. Ivanov ◽  
A. A. Pronin ◽  
N. A. Demidenko
Keyword(s):  
Mouth Zone

Geochemistry of channel drifts of the Kai River (Vietnam) and sediments of its mouth zone

Oceanology ◽  
2014 ◽  
Vol 54 (6) ◽  
pp. 788-797 ◽  
Author(s):  
G. N. Baturin ◽  
N. V. Lobus ◽  
V. I. Peresypkin ◽  
V. T. Komov
Keyword(s):  
Mouth Zone

scholarly journals The invertebrate colonization during decomposition of Eichhornia azurea kunth in a lateral lake in the mouth zone of Paranapanema River into Jurumirim Reservoir (São Paulo, Brazil)

2002 ◽  
Vol 62 (2) ◽  
pp. 293-310 ◽  
Author(s):  
N. de L. STRIPARI ◽  
R. HENRY
Keyword(s):  
Decomposition Rate ◽  
Rainy Season ◽  
Dry Season ◽  
Material Loss ◽  
Litter Bags ◽  
Eichhornia Azurea ◽  
Mouth Zone ◽  
Dry Seasons ◽  
Invertebrate Colonization

The invertebrate colonization during decomposition of Eichhornia azurea was observed in a lateral lake in the mouth zone of Paranapanema River into Jurumirim Reservoir in two periods of the year. The litter bags method was used for measuring the decomposition rate as well as to evaluate the invertebrates colonization. Forty-two litter bags, measuring 15 × 20 cm in size and 2 mm mesh net, were incubated "in situ". Six litter bags (three for colonization and three for decomposition measurements) were removed after the 1st, 3rd, 7th, 14th, 28th, 56th and 72nd days of incubation. After each day, the material was carefully cleaned for detritus removal and invertebrate sampling. The biological material was fixed with 4% formaline and then sorted and identified. The remaining plant material was dried in an oven (at 60ºC) and weighed. A fast material loss occurred during the first 24 hours and the decomposition rate was higher during the rainy season than in the dry season. A peak on invertebrate density (110 ind.g.DW--1) on the remaining detritus of Eichhornia azurea was recorded in the 56th day of dry season, when the polyphenol concentration of plant detritus was 0.57 UDO.g.DW--1. In the rainy season, higher density was found in the 28th day of incubation, when the polyphenol concentration was 4.36 UDO.g.DW--1. Apparently, the reduction in the polyphenol concentration was followed by an increase in invertebrate densities. The majority of the species observed in the detritus belongs to the collector group that was dominant after the 7th and 14th days in the rainy and dry seasons, respectively.

scholarly journals Plankton Richness and Abundance in Several Different Hydrological Situations in Lakes Lateral to a River: A Case Study in the Mouth Zone of a Tributary into a Tropical Reservoir

2011 ◽  
Vol 15 (3) ◽  
pp. 537-558 ◽  
Author(s):  
Raoul Henry ◽  
Eliana Aparecida Panarelli ◽  
Silvia Maria Caglierani Casanova ◽  
Danielli Cristina Granado ◽  
Rafael Campanelli Mortari ◽  
...  
Keyword(s):  
Tropical Reservoir ◽  
Mouth Zone

scholarly journals Benthic macroinvertebrates in the Paranapanema reservoir cascade (southeast Brazil)

2008 ◽  
Vol 68 (4 suppl) ◽  
pp. 1013-1024 ◽  
Author(s):  
A. Jorcin ◽  
MG. Nogueira
Keyword(s):  
Benthic Macroinvertebrates ◽  
River Mouth ◽  
Benthic Fauna ◽  
High Water ◽  
Paraná River ◽  
Trophic Conditions ◽  
Parana River ◽  
Southeast Brazil ◽  
Mouth Zone ◽  
Lower Depth

In this study, the composition, specific richness and abundance of benthic macroinvertebrates (<250 µm) from sediments of eight reservoirs of the Paranapanema River (southeast Brazil), as well as from the main tributaries (Taquari, Pardo and Tibagi) and the mouth zone into the Paraná River were analyzed. Nineteen points distributed along 700 km were sampled quarterly (8 campaigns) during a two-year period (2000 and 2001). The zoobenthos was characterized by a high species richness, (c.a. 100 taxa), with the predominance of Diptera Chironomidae (c.a. 50 taxa). There was a great spatial variation in the assemblage structure, mainly when compared the lacustrine zones of the reservoirs in relation to the fluvial stretches. The Oligochaeta Narapa bonettoi was dominant in sampling stations with sandy sediments and high water velocity, mainly in the Pardo River and in the upstream and downstream of the Paranapanema river mouth (Paraná River). Branchiura sowerbyi, other numerically important Oligochaeta, was abundant in regions of the upper and middle Paranapanema basin. The mollusk bivalve Corbicula fluminea was widely distributed, occurring in most stations and sampling periods. A certain increment in richness and abundance of taxa occurred in the middle Paranapanema. Lower depth, higher flow and increase in the trophic conditions seem to favor the benthic fauna development in this region. A seasonal variation pattern during the two years of study could not be detected, especially concerning the zoobenthos abundance.

scholarly journals Decadal morphological evolution of the mouth zone of the Yangtze Estuary in response to human interventions

2019 ◽  
Vol 44 (12) ◽  
pp. 2319-2332 ◽  
Author(s):  
Chunyan Zhu ◽  
Leicheng Guo ◽  
Dirk Sebastiaan Maren ◽  
Bo Tian ◽  
Xianye Wang ◽  
...  
Keyword(s):  
Morphological Evolution ◽  
Yangtze Estuary ◽  
The Yangtze Estuary ◽  
Human Interventions ◽  
Mouth Zone

scholarly journals Behaviour and distribution of heavy metals at the boundary of “water-bottom sediments” in mouth zones of rivers

2021 ◽  
Vol 265 ◽  
pp. 02016
Author(s):  
Anna Mikhailenko ◽  
Irina Dotsenko ◽  
Asya Ovsepyan ◽  
Alina Zimovets
Keyword(s):  
Heavy Metals ◽  
Hydrogen Sulfide ◽  
Bottom Sediments ◽  
Total Content ◽  
Organic Pollution ◽  
Methane Content ◽  
Anthropogenic Landscapes ◽  
Natural Man ◽  
Mouth Zone

The aquatic elementary landscapes of the Don and Northern Dvina Rivers mouth zones as arenas of mass transfer of heavy metals (HM) are studied. The results of long-term comprehensive studies of the authors, which included sampling of water and the upper layer of bottom sediments in order to determine the content of mercury, copper, methane, hydrogen sulfide, as well as pH and Eh values, are presented. According to the type of prevailing geochemical conditions and the level of anthropogenic impact, natural, man-made and natural-anthropogenic aquatic elementary landscapes are distinguished. The bottom water layers in both rivers were characterized by positive Eh values, but it should be noted that they were generally relatively low for surface watercourses. According to the values of the redox potential and the hydrogen index, the methane content and the total hydrogen sulfide, the presence of the following conditions is proved – oxygen, gley, hydrogen sulfide, oxygen-gley and gley-hydrogen sulfide. At the water - sediment interface, in most cases, there was a decrease in pH values by the first tenths of the values, while Eh usually decreased quite sharply, often to negative values. In terms of methane content, the bottom sediments of the aquatic elementary landscapes of the Don and Northern Dvina rivers were similar, while the concentration of total hydrogen sulfide was higher in the Don. It is shown that in the mouth zone of the Don and Northern Dvina rivers, in areas subject to constant organic pollution and eutrophication, there is an increase in the total content of mercury and copper in the bottom sediments. Higher concentrations of gross mercury will generally be found in natural and anthropogenic landscapes dominated by hydrogen sulfide and gley-hydrogen sulfide environments. The important role of microparticles of the polydisperse medium of bottom sediments in the deposition of copper and mercury is revealed.

Sign in / Sign up

Export Citation Format

Share Document